High Efficacy of Ivermectin for Strongyloidiasis Treatment.

Infection with Strongyloides stercoralis is often asymptomatic but can be life-threatening in immunocompromised patients, which can be prevented by ivermectin (IVM) treatment. The efficacy of IVM has been reported to have lessened over time in some regions as a consequence of prolonged use and mass treatment campaigns. Ivermectin has been used in Thailand for more than a decade; therefore, we investigated the efficacy of a single dose (200 µg/kg) of IVM against in asymptomatic strongyloidiasis in northeastern Thailand. Fecal samples were collected before and 2 weeks after treatment and were analyzed for the presence of Strongyloides using a modified agar plate culture and the formalin-ethyl acetate concentration technique. Our results showed that single-dose IVM treatment successfully eliminated S. stercoralis infection in asymptomatic individuals in the endemic area with a 100% cure rate, indicating the high efficacy of IVM treatment in strongyloidiasis in northeast Thailand.

Strongyloides stercoralis infection reduces Fusicatenibacter and Anaerostipes in the gut and increases bacterial amino-acid metabolism in early-stage chronic kidney disease.

Understanding gut bacterial composition and proteome changes in patients with early-stage chronic kidney disease (CKD) could lead to better methods of controlling the disease progression. Here, we investigated the gut microbiome and microbial functions in patients with S. stercoralis infection (strongyloidiasis) and early-stage CKD. Thirty-five patients with early stages (1-3) of CKD were placed in two groups matched for population characteristics and biochemical parameters, 12 patients with strongyloidiasis in one group and 23 uninfected patients in the other. From every individual, a sample of their feces was obtained and processed for 16S rRNA sequencing and metaproteomic analysis using tandem liquid chromatography-mass spectrometry (LC-MS/MS). Strongyloides stercoralis infection per se did not significantly alter gut microbial diversity. However, certain genera (Bacteroides, Faecalibacterium, Fusicatenibacter, Sarcina, and Anaerostipes) were significantly more abundant in infection-free CKD patients than in infected individuals. The genera Peptoclostridium and Catenibacterium were enriched in infected patients. Among the significantly altered genera, Fusicatenibacter and Anaerostipes were the most correlated with renal parameters. The relative abundance of members of the genus Fusicatenibacter was moderately positively correlated with estimated glomerular filtration rate (eGFR) (r = 0.335, p = 0.049) and negatively with serum creatinine (r = -0.35, p = 0.039). Anaerostipes, on the other hand, showed a near-significant positive correlation with eGFR (r = 0.296, p = 0.084). Individuals with S. stercoralis infection had higher levels of bacterial proteins involved in amino-acid metabolism. Analysis using STITCH predicted that bacterial amino-acid metabolism may also be involved in the production of colon-derived uremic toxin (indole), a toxic substance known to promote CKD. Strongyloides stercoralis infection is, therefore, associated with reduced abundance of Fusicatenibacter and Anaerostipes (two genera possibly beneficial for kidney function) and with increased bacterial amino-acid metabolism in the early-stages of CKD, potentially producing uremic toxin. This study provides useful information for prevention of progression of CKD beyond the early stages.

Diagnostic performance of Strongyloides-specific IgG4 detection in urine for diagnosis of human strongyloidiasis.

BACKGROUND: Detection of parasite-specific IgG in urine is a sensitive method for diagnosis of strongyloidiasis and gives similar accuracy to serum IgG. However, there are no data concerning detection of IgG subclass in urine. To further explore the utility of diagnosis from urine samples, we evaluated the diagnostic performance of IgG4 in urine compared with parasitological and other immunological methods. METHODS: The urine and sera included proven strongyloidiasis (group 1, n = 93), other parasitic infections (group 2, n = 40) and parasite negatives (group 3, n = 93). The performance of Strongyloides-specific IgG4 in urine for diagnosis of strongyloidiasis using fecal examinations as the reference standard was assessed. RESULTS: With fecal examination as a gold standard, Strongyloides-specific IgG4 in urine had 91.4% sensitivity and 93.2% specificity while serum IgG4 had 93.6% sensitivity and 91.0% specificity. IgG4 in both urine and serum had almost perfect diagnostic agreements with fecal examination (Cohen's kappa coefficient was > 0.8). Cross-reactivity to Opisthorchis viverrini and Taenia spp. of IgG4 in urine were 7.5% and 12.5% in serum. Concurrent analyses of total IgG in urine and serum showed that the sensitivities (97.9-100%) and specificities (88.7-91.0%) were similar (P > 0.05). The sensitivity for parasitological examination by the formalin-ethyl acetate concentration technique (FECT) was 49.5% and that for agar plate culture technique (APC) it was 92.6%. CONCLUSION: Our findings showed that specific IgG4 detection in urine yielded similar diagnostic performance to the same biomarkers in serum. This suggests that accurate diagnosis of strongyloidiasis can be performed using urine samples and IgG4 is a valid choice of diagnostic marker. Further assessment is required to assess the utility of urine IgG4 for measuring the response treatment in strongyloidiasis.

Chronic Strongyloides stercoralis infection increases presence of the Ruminococcus torques group in the gut and alters the microbial proteome.

We explored the impact of chronic Strongyloides stercoralis infection on the gut microbiome and microbial activity in a longitudinal study. At baseline (time-point T0), 42 fecal samples from matched individuals (21 positive for strongyloidiasis and 21 negative) were subjected to microbiome 16S-rRNA sequencing. Those positive at T0 (untreated then because of COVID19 lockdowns) were retested one year later (T1). Persistent infection in these individuals indicated chronic strongyloidiasis: they were treated with ivermectin and retested four months later (T2). Fecal samples at T1 and T2 were subjected to 16S-rRNA sequencing and LC-MS/MS to determine microbial diversity and proteomes. No significant alteration of indices of gut microbial diversity was found in chronic strongyloidiasis. However, the Ruminococcus torques group was highly over-represented in chronic infection. Metaproteome data revealed enrichment of Ruminococcus torques mucin-degrader enzymes in infection, possibly influencing the ability of the host to expel parasites. Metaproteomics indicated an increase in carbohydrate metabolism and Bacteroidaceae accounted for this change in chronic infection. STITCH interaction networks explored highly expressed microbial proteins before treatment and short-chain fatty acids involved in the synthesis of acetate. In conclusion, our data indicate that chronic S. stercoralis infection increases Ruminococcus torques group and alters the microbial proteome.

Prevalence of gastrointestinal parasites in captive mammals at Khon Kaen Zoo, Thailand.

Background and Aim: Captive animals are susceptible to parasitic diseases due to the stress and confinement they experience. In addition, they can serve as reservoirs of zoonotic parasites that have the potential to infect humans. To investigate this possibility, we estimated the prevalence of gastrointestinal (GI) parasites in captive mammals at Khon Kaen Zoo, Thailand. Materials and Methods: One hundred and forty-seven individual mammals (37 primates, 43 carnivores, 62 herbivores, and 5 rodents) were examined for parasitic infections by fecal examination daily for 3 consecutive days using the formalin-ethyl acetate concentration technique (FECT) and the agar plate culture method. Results: According to FECT, the overall prevalence of GI parasites was 62.6% (92/147). Within animal groups, the numbers were as follows: 67.6% (25/37) in primates, 23.3% (10/43) in carnivores, 85.5% (53/62) in herbivores, and 80.0% (4/5) in rodents. Using the agar plate culture method, 21.43% (27/126) were positive for Strongyloides spp. and hookworm infections. The GI parasites identified belonged to three categories: protozoa (including Entamoeba histolytica species complex, Entamoeba coli, Giardia spp., coccidia, and ciliated protozoa), trematodes (minute intestinal flukes and rumen flukes), and nematodes (strongyle/hookworm, Strongyloides spp., Ascarididae, and Trichuris spp.). Conclusion: The findings of this study indicate the prevalence of several GI parasites in zoo animals with the potential for transmission to humans, given the animals' close proximity to both visitors and animal caretakers.

Strongyloides stercoralis infection induces gut dysbiosis in chronic kidney disease patients.

BACKGROUND: Strongyloides stercoralis infection typically causes severe symptoms in immunocompromised patients. This infection can also alter the gut microbiota and is often found in areas where chronic kidney disease (CKD) is common. However, the relationship between S. stercoralis and the gut microbiome in chronic kidney disease (CKD) is not understood fully. Recent studies have shown that gut dysbiosis plays an important role in the progression of CKD. Hence, this study aims to investigate the association of S. stercoralis infection and gut microbiome in CKD patients. METHODOLOGY/PRINCIPAL FINDINGS: Among 838 volunteers from Khon Kaen Province, northeastern Thailand, 40 subjects with CKD were enrolled and divided into two groups (S. stercoralis-infected and -uninfected) matched for age, sex and biochemical parameters. Next-generation technology was used to amplify and sequence the V3-V4 region of the 16S rRNA gene to provide a profile of the gut microbiota. Results revealed that members of the S. stercoralis-infected group had lower gut microbial diversity than was seen in the uninfected group. Interestingly, there was significantly greater representation of some pathogenic bacteria in the S. stercoralis-infected CKD group, including Escherichia-Shigella (P = 0.013), Rothia (P = 0.013) and Aggregatibacter (P = 0.03). There was also a trend towards increased Actinomyces, Streptococcus and Haemophilus (P > 0.05) in this group. On the other hand, the S. stercoralis-infected CKD group had significantly lower representation of SCFA-producing bacteria such as Anaerostipes (P = 0.01), Coprococcus_1 (0.043) and a non-significant decrease of Akkermansia, Eubacterium rectale and Eubacterium hallii (P > 0.05) relative to the uninfected group. Interesting, the genera Escherichia-Shigella and Anaerostipes exhibited opposing trends, which were significantly related to sex, age, infection status and CKD stages. The genus Escherichia-Shigella was significantly more abundant in CKD patients over the age of 65 years and infected with S. stercoralis. A correlation analysis showed inverse moderate correlation between the abundance of the genus of Escherichia-Shigella and the level of estimated glomerular filtration rate (eGFR). CONCLUSIONS/SIGNIFICANCE: Conclusion, the results suggest that S. stercoralis infection induced gut dysbiosis in the CKD patients, which might be involved in CKD progression.

Curcumin-loaded nanocomplexes ameliorate the severity of nonalcoholic steatohepatitis in hamsters infected with Opisthorchis viverrini.

BACKGROUND: Comorbidity of Opisthorchis viverrini (OV) infection and nonalcoholic fatty-liver disease (NAFLD) enhances NAFLD progression to nonalcoholic steatohepatitis (NASH) by promoting severe liver inflammation and fibrosis. Here, we investigated the effect of supplementation with curcumin-loaded nanocomplexes (CNCs) on the severity of NASH in hamsters. METHODOLOGY: Hamsters were placed in experimental groups as follows: fed standard chow diet (normal control, NC); fed only high-fat and high-fructose (HFF) diet; O. viverrini-infected and fed HFF diet (HFFOV); group fed with blank nanocomplexes (HFFOV+BNCs); groups fed different doses of CNCs (25, 50 and 100 mg/kg body weight: HFFOV+CNCs25; HFFOV+CNCs50; HFFOV+CNCs100, respectively) and a group given native curcumin (HFFOV+CUR). All treatment were for three months. RESULTS: The HFF group revealed NAFLD as evidenced by hepatic fat accumulation, ballooning, mild inflammation and little or no fibrosis. These changes were more obvious in the HFFOV group, indicating development of NASH. In contrast, in the HFFOV+CNCs50 group, histopathological features indicated that hepatic fat accumulation, cell ballooning, cell inflammation and fibrosis were lower than in other treatment groups. Relevantly, the expression of lipid-uptake genes, including fatty-acid uptake (cluster of differentiation 36), was reduced, which was associated with the lowering of alanine aminotransferase, total cholesterol and triglyceride (TG) levels. Reduced expression of an inflammation marker (high-mobility group box protein 1) and a fibrosis marker (alpha smooth-muscle actin) were also observed in the HFFOV+CNCs50 group. CONCLUSION: CNCs treatment attenuates the severity of NASH by decreasing hepatic steatosis, inflammation, and fibrosis as well as TG synthesis. CNCs mitigate the severity of NASH in this preclinical study, which indicates promise for future use in patients.

Investigation of gut microbiota and short-chain fatty acids in Strongyloides stercoralis-infected patients in a rural community.

Intestinal parasitic infections can change gut microbiota and short-chain fatty acids (SCFAs). We aimed to study the interaction among Strongyloides stercoralis, human gut microbiota, and serum SCFAs in a community. Fifty-two subjects in Donchang sub-district, Khon Kaen Province, northeastern Thailand, were included based on specific inclusion and exclusion criteria. Characteristics of the participants were matched between those positive for S. stercoralis infection alone (no other intestinal parasites; Ss+, n=26) and uninfected controls (infection status confirmed by polymerase chain reaction (PCR); Ss-, n=26). Serum short-chain fatty acids were evaluated by gas chromatography-mass spectrometry. DNA was extracted from individual faecal samples and then pooled into two groups (Ss+ and Ss-) for amplification and sequencing of the V3-V4 region of the 16S gene with next-generation technology. We explored the impact of infection with S. stercoralis on the faecal microbiota: individuals infected with this parasite exhibited increased alpha diversity of bacteria. At the genus level, gut microbiota in Ss+ patients showed high abundances of Escherichia-Shigella and Bacteroides but low abundances of the genera Bifidobacterium, Lactobacillus, and Blautia. PCR of individual samples to identify certain species of interest gave results consistent with those from next-generation sequencing of pooled samples and showed that significantly more Ss+ samples contained Bacteroides fragilis. Intriguingly, a major SCFA, acetic acid, was significantly decreased in S. stercoralis infection. In conclusion, S. stercoralis infection caused an imbalance of gut microbiota and decreased acetic acid in serum. This information adds to the knowledge concerning the effect of intestinal nematode-related chronic diseases.

A newly developed droplet digital PCR for Ehrlichia canis detection: comparisons to conventional PCR and blood smear techniques.

Canine monocytic ehrlichiosis caused by Ehrlichia canis infection is a life-threatening vector-borne disease in dogs worldwide. Routine blood smear has very low sensitivity and cannot accurately provide a quantitative result. Conventional PCR (cPCR) and real-time PCR (qPCR) are widely used as molecular methods for E. canis detection. qPCR is quantitative but relies on standard curves of known samples. To overcome this difficulty, this study developed a new E. canis quantitative detection method, using droplet digital polymerase chain reaction (ddPCR). ddPCR was evaluated against cPCR and blood smears. PCR amplicons and genomic DNA (gDNA) from 12 microscopic positive samples were used to identify the limits of detection (LODs) in ddPCR and cPCR. Our ddPCR was assessed in 92 field samples, it was compared with cPCR and blood smears. ddPCR showed LOD=1.6 copies/reaction, or 78 times more sensitive than cPCR (LOD=126 copies/reaction), using PCR amplicons as a template, whereas both ddPCR and cPCR had equal LODs at 0.02 ng gDNA/reaction. In addition, ddPCR had 100% sensitivity and 75% specificity for E. canis detection compared to cPCR and no cross-reaction with other blood pathogens was observed. ddPCR identified more positive samples than cPCR and blood smear. ddPCR improved the overall performance of E. canis detection, with a better LOD and comparable sensitivity and specificity to cPCR. The technique might be helpful for diagnosis of E. canis in light infection, evaluating the number of E. canis and follow-up after treatment.

Development and Efficacy of Droplet Digital PCR for Detection of Strongyloides stercoralis in Stool.

Human strongyloidiasis is one of the neglected tropical diseases caused by infection with soil-transmitted helminth Strongyloides stercoralis. Conventional stool examination, a method commonly used for diagnosis of S. stercoralis, has low sensitivity, especially in the case of light infections. Herein, we developed the droplet digital polymerase chain reaction (ddPCR) assay to detect S. stercoralis larvae in stool and compared its performance with real-time PCR and stool examination techniques (formalin ethyl-acetate concentration technique [FECT] and agar plate culture [APC]). The ddPCR results showed 98% sensitivity and 90% specificity, and real-time PCR showed 82% sensitivity and 76.7% specificity when compared with the microscopic methods. Moreover, ddPCR could detect a single S. stercoralis larva in feces, and cross-reactions with other parasites were not observed. In conclusion, a novel ddPCR method exhibited high sensitivity and specificity for detection of S. stercoralis in stool samples. This technique may help to improve diagnosis, particularly in cases with light infection. In addition, ddPCR technique might be useful for screening patients before starting immunosuppressive drug therapy, and follow-up after treatment of strongyloidiasis.

Overexpression of AGR2vH, an oncogenic AGR2 spliced transcript, potentiates tumorigenicity and proteomic alterations in cholangiocarcinoma cell.

The upregulation of anterior gradient 2 (AGR2) has been observed in cholangiocarcinoma (CCA) cells, nras-mutant zebrafish, and specimens derived from CCA patients. Our previous study reported AGR2 splicing into AGR2vH to facilitate CCA cell aggressiveness, while this work aims to investigate the molecular mechanisms underlying AGR2vH. First, AGR2vH upregulation was demonstrated in CCA tissues derived from patients. For in vitro studies, established AGR2vH-overexpressing KKU-213A cells were found to exhibit increased proliferation and clonogenicity. In vivo tumorigenicity assessed in a mouse model represented higher tumorigenic potential in AGR2vH-overexpressing cell xenograft mice. Next, LC-MS/MS was analyzed, indicating that AGR2vH may be associated with CCA cell proliferation via Wnt/ß-catenin signaling pathway activation, which was verified by ß-catenin expression and nuclear translocation. The current results provide evidence that AGR2vH upregulation promotes tumorigenicity in CCA cells linked with an alteration of CCA cell proteome.

Repeated Ivermectin Treatment Induces Ivermectin Resistance in Strongyloides ratti by Upregulating the Expression of ATP-Binding Cassette Transporter Genes.

Ivermectin (IVM) is a widely used anthelmintic. However, with widespread use comes the risk of the emergence of IVM resistance, particularly in strongyloidiasis. Adenosine triphosphate (ATP)-binding cassette (ABC) transporter genes play an important role in the IVM-resistance mechanism. Here, we aimed to establish an animal experimental model of IVM resistance by frequent treatment of Strongyloides ratti with subtherapeutic doses of IVM, resistance being evaluated by the expression levels of ABC transporter genes. Rats infected with S. ratti were placed in experimental groups as follows: 1) untreated control (control); 2) treated with the mutagen ethyl methanesulfonate (EMS); 3) injected with 100 µg/kg body weight of IVM (IVM); 4) treated with a combination of EMS and IVM (IVM+EMS). Parasites were evaluated after four generations. Extent of IVM resistance was assessed using IVM sensitivity, larval development, and expression of ABC genes. By the F4 generation, S. ratti in the IVM group exhibited significantly higher levels of IVM resistance than did other groups according to in vitro drug-sensitivity tests and inhibition of larval development (IC50 = 36.60 ng/mL; 95% CI: 31.6, 42.01). Expression levels of ABC isoform genes (ABCA, ABCF, and ABCG) were statistically significantly higher in the IVM-resistant line compared with the susceptible line. In conclusion, IVM subtherapeutic doses induced IVM resistance in S. ratti by the F4 generation with corresponding upregulation of some ABC isoform genes. The study provides a model for inducing and assessing drug resistance in Strongyloides.

An optimized agar plate culture improves diagnostic efficiency for Strongyloides stercoralis infection in an endemic community.

We aimed to compare the efficacy of modified agar plate fecal culture (mAPC) and standard agar plate culture (sAPC) for diagnosis of Strongyloides stercoralis infection in a community at Khon Kaen Province, Thailand. Fecal samples were collected from participants individually (n = 1076) and were tested using these two methods. Modified APC and sAPC detected 129 (11.99%) and 91 (8.46%) infected individuals, respectively. Thirty-eight participants were negative according to sAPC, but positive for mAPC. Moreover, in the participants who were positive for both methods, the number of worm developmental stages obtained was higher for mAPC than for sAPC. Our study suggests that mAPC is an effective and useful tool for S. stercoralis diagnosis and can be applied for mass-screening in community and/or control programs.

Partial protection with a chimeric tetraspanin-leucine aminopeptidase subunit vaccine against Opisthorchis viverrini infection in hamsters.

Opisthorchiasis is a serious public health problem in East Asia and Europe. The pathology involves hepatobiliary abnormalities such as cholangitis, choledocholithiasis and tissue fibrosis that can develop into cholangiocarcinoma. Prevention of infection is difficult as multiple social and behavioral factors are involved, thus, progress on a prophylactic vaccine against opisthorchiasis is urgently needed. Opisthorchis viverrini tetraspanin-2 (Ov-TSP-2) was previously described as a potential vaccine candidate conferring partial protection against O. viverrini infections in hamsters. In this study, we generated a recombinant chimeric form of the large extracellular loop of Ov-TSP-2 and O. viverrini leucine aminopeptidase, designated rOv-TSP-2-LAP. Hamsters were vaccinated with 100 and 200 µg of rOv-TSP-2-LAP formulated with alum-CpG adjuvant via intraperitoneal injection and evaluated the level of protection against O. viverrini infection. Our results demonstrated that the number of worms recovered from hamsters vaccinated with either 100 or 200 µg of rOv-TSP-2-LAP were significantly reduced by 27% compared to the adjuvant control group. Furthermore, the average length of worms recovered from animals vaccinated with 200 µg of rOv-TSP-2-LAP was significantly shorter than those from the control adjuvant group. Immunized hamsters showed significantly increased serum levels of anti-rOv-TSP-2 IgG and IgG1 compared to adjuvant control group, suggesting that rOv-TSP-2-LAP vaccination induces a mixed Th1/Th2 immune response in hamsters. Therefore, the development of a suitable vaccine against opisthorchiasis requires further work involving new vaccine technologies to improve immunogenicity and protective efficacy.

Recombinant Opisthorchis viverrini tetraspanin expressed in Pichia pastoris as a potential vaccine candidate for opisthorchiasis.

Opisthorchiasis affects millions of people in Southeast Asia and has been strongly associated with bile duct cancer. Current strategic control approaches such as chemotherapy and health education are not sustainable, and a prophylactic vaccine would be a major advance in the prevention of the disease. Tetraspanins are transmembrane proteins previously described as potential vaccine candidates for other helminth infections and are also found in the membranes of the tegument and extracellular vesicles of O. viverrini. Here, we investigated the potential of a recombinant protein encoding for the large extracellular loop of O. viverrini tetraspanin-2 (rOv-LEL-TSP-2) in a hamster vaccination model. Hamsters were vaccinated with 50 and 100 µg of rOv-LEL-TSP-2 produced from Pichia pastoris yeast combined with alum CpG adjuvant via the intraperitoneal route. The number of worms recovered from hamsters vaccinated with rOv-LEL-TSP-2 was significantly reduced compared to adjuvant control groups. Fecal egg output was also significantly reduced in vaccinated animals, and the average length of worms recovered from vaccinated animals was significantly shorter than that of the control group. Vaccinated animals showed significantly increased levels of anti-rOv-TSP-2 IgG in the sera after three immunizations, as well as increased levels of several T helper type 1 cytokines in the spleen including IFN-γ and IL-6 but not the Th2/regulatory cytokines IL-4 or IL-10. These results suggest that rOv-TSP-2 could be a potential vaccine against opisthorchiasis and warrants further exploration.

Discovering proteins for chemoprevention and chemotherapy by curcumin in liver fluke infection-induced bile duct cancer.

Modulation or prevention of protein changes during the cholangiocarcinoma (CCA) process induced by Opisthorchis viverrini (Ov) infection may become a key strategy for prevention and treatment of CCA. Monitoring of such changes could lead to discovery of protein targets for CCA treatment. Curcumin exerts anti-inflammatory and anti-CCA activities partly through its protein-modulatory ability. To support the potential use of curcumin and to discover novel target molecules for CCA treatment, we used a quantitative proteomic approach to investigate the effects of curcumin on protein changes in an Ov-induced CCA-harboring hamster model. Isobaric labelling and tandem mass spectrometry were used to compare the protein expression profiles of liver tissues from CCA hamsters with or without curcumin dietary supplementation. Among the dysregulated proteins, five were upregulated in liver tissues of CCA hamsters but markedly downregulated in the CCA hamsters supplemented with curcumin: S100A6, lumican, plastin-2, 14-3-3 zeta/delta and vimentin. Western blot and immunohistochemical analyses also showed similar expression patterns of these proteins in liver tissues of hamsters in the CCA and CCA + curcumin groups. Proteins such as clusterin and S100A10, involved in the NF-κB signaling pathway, an important signaling cascade involved in CCA genesis, were also upregulated in CCA hamsters and were then suppressed by curcumin treatment. Taken together, our results demonstrate the important changes in the proteome during the genesis of O. viverrini-induced CCA and provide an insight into the possible protein targets for prevention and treatment of this cancer.

Cytokine/chemokine secretion and proteomic identification of upregulated annexin A1 from peripheral blood mononuclear cells cocultured with the liver fluke Opisthorchis viverrini.

We investigated the cytokine/chemokine secretions and alteration of protein expression from peripheral blood mononuclear cells (PBMCs) cocultured with adult liver flukes (Opisthorchis viverrini) for 6 to 24 h. PBMC-derived proteins were identified by two-dimensional electrophoresis and mass spectrometry, and the cytokines/chemokines in the supernatant were assessed using a cytokine array. Exposure to O. viverrini induced increases in secretion of proinflammatory cytokines, costimulating protein, adhesion molecules, and chemotactic chemokines relative to untreated controls. In contrast, secretion of the CD40 ligand, interleukin 16, and macrophage inflammatory protein 1ß decreased. Proteomic analysis revealed that expression of 48 proteins was significantly altered in PBMCs stimulated with O. viverrini. Annexin A1 (ANXA1) was selected for further study, and immunoblotting showed upregulation of ANXA1 expression in PBMCs after 12 and 24 h coculture with liver flukes. In an in vivo study, transcription and translation of ANXA1 significantly increased in livers of hamsters infected with O. viverrini at 21 days and from 3 months onwards compared to normal controls. Interestingly, immunohistochemistry revealed that ANXA1 was present not only in the cytoplasm of inflammatory cells but also in the cytoplasm of cholangiocytes, which are in close contact with the parasite and its excretory/secretory products in the biliary system. Expression of ANXA1 increased with time concomitant with bile duct enlargement, bile duct formation, and epithelial cell proliferation. In conclusion, several cytokines/chemokines secreted by PBMCs and upregulation of ANXA1 in PBMCs and biliary epithelial cells might have a role in host defense against O. viverrini infection and tissue resolution of inflammation.

Increase of exostosin 1 in plasma as a potential biomarker for opisthorchiasis-associated cholangiocarcinoma.

A proteomic-based approach was used to search for potential markers in the plasma of hamsters in which cholangiocarcinoma (CCA) was induced by Opisthorchis viverrini infection and N-nitrosodimethylamine treatment. The plasma proteins of CCA-induced hamsters were resolved by 1-D PAGE, digested by trypsin, and analyzed by LC-MS/MS. From the criteria of protein ID scores >15 and an overexpression of at least three times across all time points, 37 proteins were selected. These overexpressed proteins largely consisted of signal transduction, structural, transport, and transcriptional proteins in the order. Among the most frequently upregulated proteins, exostosin 1 (EXT1) was selected for further validation. By western blot analysis, the EXT1 expression level in the plasma of hamster CCA was significantly higher than that of controls at 1 month and thereafter. Immunohistochemistry revealed that EXT1 was expressed at vascular walls and fibroblasts at 21 days (before tumor onset) and at 2 months (early CCA) posttreatment. Its expression was also observed in bile duct cancer cells during tumor progression at 6 months posttreatment. In the human CCA tissue microarray, EXT1 immunoreactivity was found not only in vascular walls and fibroblasts but also in bile duct cancer cells and was positive in 89.7 % (61/68) of the cases. By ELISA and immunoblotting, plasma EXT1 level was significantly higher in human CCA compared to healthy controls. In conclusion, these results suggest that increased expression of EXT1 level in the plasma might be involved in CCA genesis and might be a potential biomarker of CCA.

Annexin A1: A new immunohistological marker of cholangiocarcinoma.

AIM: To evaluate a new immunohistological marker, annexin A1 (ANXA1), in cholangiocarcinoma (CCA) and hepatocellular carcinoma (HCC). METHODS: Expression of ANXA1 protein was investigated in liver tissues from patients with CCA and HCC by immunohistochemistry. Its expression on differences stages of tumor development was investigated in hamster CCA tissues induced by Opisthorchis viverrini and N-nitrosodimethylamine. Moreover, mRNA expression of ANXA1 was assessed in CCA cell lines by quantitative real-time polymerase chain reaction and silencing of ANXA1 gene expression using small interfering RNA. RESULTS: In human CCA tissue arrays, immunohistochemical analysis revealed that the positive expression of ANXA1 was 94.1% (64/68 cases) consisting of a high expression (66.2%, 45/68 cases) and a low expression (33.8%, 23/68 cases). However, expression of ANXA1 protein was negative in all histologic patterns for HCC (46/46 cases) and healthy individuals (6/6 cases). In hamster with opisthorchiasis-associated CCA, the expression of ANXA1 was observed in the cytoplasm of inflammatory cells, bile duct epithelia and tumor cells. Grading scores of ANXA1 expression were significantly increased with tumor progression. In addition, mRNA expression of ANXA1 significantly increased in all of the various CCA cell lines tested compared to an immortalized human cholangiocyte cell line (MMNK1). Suppressing the ANXA1 gene significantly reduced the matrix metalloproteinase (MMP) 2 and MMP9, and transforming growth factor-ß genes, but increased nuclear factor-κB gene expression. CONCLUSION: ANXA1 is highly expressed in CCA, but low in HCC, suggesting it may serve as a new immunohistochemical marker of CCA. ANXA1 may play a role in opisthorchiasis-associated cholangiocarcinogenesis.

Distribution and abundance of Opisthorchis viverrini metacercariae in cyprinid fish in Northeastern Thailand.

To increase public health awareness for prevention of opisthorchiasis caused by eating raw freshwater fish, the distribution and abundance of Opisthorchis viverrini metacercariae (OV MC) was investigated in freshwater fish obtained from 20 provinces in northeastern Thailand between April 2011 and February 2012. A cross-sectional survey was conducted on 12,890 fish consisting of 13 species randomly caught from 26 rivers, 10 dams, and 38 ponds/lakes. Fish, were collected in each of the rainy and winter seasons from each province. Fish were identified, counted, weighed, and digested using pepsin-HCl. Samples were examined for OV MC by a sedimentation method, and metacercariae were identified under a stereomicroscope. OV MC were found in 6 species of fish; i.e., Cyclocheilichthys armatus, Puntius orphoides, Hampala dispar, Henicorhynchus siamensis, Osteochilus hasselti, and Puntioplites proctozysron from localities in 13 provinces. Among the sites where OV MC-infected fish were found, 70.0% were dams, 23.7% were ponds/lakes, and 7.7% were rivers. The mean intensity of OV MC ranged from 0.01 to 6.5 cysts per fish (or 1.3-287.5 cysts per kg of fish). A high mean intensity of OV MC per fish (>3 cysts) was found in 5 provinces: Amnat Charoen (6.5 cysts), Nakhon Phanom (4.3), Mukdahan (4.1), Khon Kaen, (3.5) and Si Sa Ket (3.4). In conclusion, OV MC are prevalent in natural cyprinid fish, with the infection rate varying according to fish species and habitats.